Watch towers and the barbed wire fence of the former Nazi death camp Majdanek. AP Photo/Czarek Sokolowski.

WARSAW (AP).- Officials say a fire broke out overnight in one of barracks of the former Nazi death camp of Majdanek, destroying more than half of the building and about 10,000 shoes of Holocaust survivors.

The Majdanek museum said the fire broke out shortly before midnight on Monday. The cause of the fire is not yet known and the experts are investigating.

In Israel, Yad Vashem Chairman Avner Shalev said "the damage to these irreplaceable items is a loss to a site that has such historical value to Europe, Poland and the Jewish people."

An estimated 80,000 people, including some 60,000 Jews, were killed at the SS-run camp near Lublin in occupied Poland between October 1941 and its liberation by Soviet troops in July 1944.